A man who climbed the Golden Gate Bridge and spent the night on the span's south tower under cover of thick fog was taken into custody shortly before 10 a.m. Friday by a California Highway Patrol SWAT unit.

The man had climbed onto the bridge's east main cable Thursday night, threatened suicide and told officers he had a gun, authorities said. The incident disrupted traffic; authorities shut down pedestrian and bicycle lanes, and the entire bridge was closed twice during the search.

CHP officers used the elevator inside the tower to apprehend the man 746 feet above the bay, where he apparently spent the night. He turned out to be unarmed, officials said.

Thick overnight fog made it difficult to keep track of the man and police were not sure of his whereabouts early Friday morning, CHP officials said.

"We can't see the top of the tower," said CHP Sgt. Diana McDermott before the man was taken into custody. "We have to wait for the fog to clear."

The 16-hour ordeal began early Thursday evening after police received reports around 6:15 p.m. that a man had climbed onto the main cable. He apparently got onto the main cable mid span and may have used paint scaffolding to gain access.

At about 8 p.m. the man climbed the cable, and then came down far enough to talk to police when they arrived. He told authorities — who began to negotiate with him — that he was armed; then he climbed back up the cable and vanished into the fog.

In addition to police negotiators, the CHP, Golden Gate Bridge authority and the U.S. Coast Guard responded.

Sidewalks were closed during the search, preventing bicyclists and pedestrians from crossing the span. Tourist Jenny Stokes, visiting from Dublin, Ireland, had come to the bridge Thursday evening to cross it but found the walkway closed. She returned Friday morning, but it had not yet reopened.

"I can't believe he stayed up there overnight," she said, looking up at the south tower ensconced in fog. "It seems impossible, it's so cold."

The incident served to back up traffic during the morning commute. At 8:33 a.m. traffic was stopped on the bridge for 10 minutes as CHP units went up the north tower via an elevator to look for the man, but they didn't find him there. Then at 9:40 a.m. traffic was stopped again for 10 minutes and the same CHP SWAT unit — in camouflage fatigues — went up the south tower elevator and the team found the man on top of the tower where he was taken into custody. The bridge walkway was reopened at 10:10 a.m.

The man was taken down the tower's elevator and medics on hand examined him before he was taken to a hospital in San Francisco. It was unclear if he would be charged.

The incident has bridge officials looking at security.

"We have pretty good access control to that cable," said Kary Witt, bridge manager. "Getting access to the cable is not easily done."

Once the man got on the cable he had to work his way around a gate on the cable before climbing to the top of the tower, Witt noted.

"He had to get around that at great, great peril to himself," Witt said. "It's a pretty formidable barrier. It's quite a feat."

Bridge officials knew right away that someone had gained access to the cable because of security sensors and cameras, but by the time officials arrived the man was out of reach.

"He got past the gate quickly and he was up into the fog," Witt said. "We have to look at this. When someone defeats your security system we want to know how he did it."

Contact IJ reporter Mark Prado at mprado@marinij.com; the Bay Area News Group contributed to this report.